Include <stddef.h>, for offsetof.

Include <stddef.h>, for offsetof.
(lbitset_bytes): Adjust to new, unique names for structures.

(lbitset_and, lbitset_and_cmp, lbitset_andn, lbitset_andn_cmp,
lbitset_or, lbitset_or_cmp, lbitset_xor, lbitset_xor_cmp,
lbitset_empty_p, lbitset_ones, lbitset_not, lbitset_subset_p,
lbitset_disjoint_p, debug_lbitset): Supply prototype decls.

(enum_lbitset_find_mode): New type.  All instances of parameters of
type enum FOO are now of type enum_FOO, to conform to the C Standard.

(struct lbitset_struct, lbitset, bitset_struct, PFV): Remove.

(lbitset_and, lbitset_andn, lbitset_or, lbitset_xor): New functions.